EZ Arms Keeper does not limit the number of Bound Books that you can create. However, you can only have one Bound Book open at a time.
There are limits depending on the Bound Book Type being used:
There is no arbitrary limit to the number of Acquisitions / Dispositions that are allowed in a Bound Book. The total number will vary by the amount of data recorded per acquisition / disposition. However, practically speaking you should be able to create to up to approximately 2 million acquisitions and 2 million dispositions with the most limited Bound Book Type.